Apparatus and methods for securing elastic to a carrier web

ABSTRACT

Apparatus and methods are provided to allow for creation of an elastic laminate. Non-stretched elastic can be laid at peaks over a nonwoven layer contained in valleys and atop peaks. Stretched elastic can be laid over tented nonwoven to create nonwoven tunnels when a second nonwoven is laid atop the first nonwoven and elastic, and the tunnels resist un-stretching of stretched elastic strands by frictional or obstruction forces. An elastic assembly or structure comprising a first and second layer of material bonded at spaced apart bond sites is disclosed, with a plurality of elastic strands disposed in a non-linear manner between said first and second layer of material, so that said strands meander in a cross-machine direction and traverse a machine direction line, restraining movement of the strands by frictional forces between the strands and the non-woven layers.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is a continuation of and claims priority to U.S.patent application Ser. No. 14/836,698 filed Aug. 26, 2015, which claimspriority to U.S. Provisional Patent Application Ser. No. 62/041,876,filed Aug. 26, 2014, the disclosures of which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

This invention relates to an apparatus and method for producing alaminate of elastic material by attaching a non-elongated elastic to acarrier web or webs. While the description provided relates to diapermanufacturing, the apparatus and methods are easily adaptable to otherapplications.

Generally, diapers comprise an absorbent insert or patch and a chassis,which, when the diaper is worn, supports the insert proximate a wearer'sbody. Additionally, diapers may include other various patches, such astape tab patches, reusable fasteners and the like. The raw materialsused in forming a representative insert are typically cellulose pulp,tissue paper, poly, nonwoven web, acquisition, and elastic, althoughapplication specific materials are sometimes utilized. Usually, most ofthe insert raw materials are provided in roll form, and unwound andapplied in assembly line fashion.

In the creation of a diaper, multiple roll-fed web processes aretypically utilized. To create an absorbent insert, the cellulose pulp isunwound from the provided raw material roll and pulverized by a pulpmill. Discrete pulp cores are formed by a core forming assembly andplaced on a continuous tissue web. Optionally, super-absorbent powdermay be added to the pulp core. The tissue web is wrapped around the pulpcore. The wrapped core is debulked by proceeding through a calenderunit, which at least partially compresses the core, thereby increasingits density and structural integrity. After debulking, thetissue-wrapped core is passed through a segregation or knife unit, whereindividual wrapped cores are cut. The cut cores are conveyed, at theproper pitch, or spacing, to a boundary compression unit.

While the insert cores are being formed, other insert components arebeing prepared to be presented to the boundary compression unit. Forinstance, the poly sheet is prepared to receive a cut core. Like thecellulose pulp, poly sheet material is usually provided in roll form.The poly sheet is fed through a splicer and accumulator, coated with anadhesive in a predetermined pattern, and then presented to the boundarycompression unit. In addition to the poly sheet, which may form thebottom of the insert, a two-ply top sheet may also be formed in parallelto the core formation. Representative plies are an acquisition webmaterial and a nonwoven web material, both of which are fed frommaterial rolls, through a splicer and accumulator. The plies are coatedwith adhesive, adhered together, cut to size, and presented to theboundary compression unit. Therefore, at the boundary compression unit,three components are provided for assembly: the poly bottom sheet, thecore, and the two-ply top sheet.

A representative boundary compression unit includes a die roller and aplaten roller. When all three insert components are provided to theboundary compression unit, the nip of the rollers properly compressesthe boundary of the insert. Thus, provided at the output of the boundarycompression unit is a string of interconnected diaper inserts. Thediaper inserts are then separated by an insert knife assembly andproperly oriented. At this point, the completed insert is ready forplacement on a diaper chassis.

A representative diaper chassis comprises nonwoven web material andsupport structure. The diaper support structure is generally elastic andmay include leg elastic, waistband elastic and belly band elastic. Thesupport structure is usually sandwiched between layers of the nonwovenweb material, which is fed from material rolls, through splicers andaccumulators. The chassis may also be provided with several patches,besides the absorbent insert. Representative patches include adhesivetape tabs and resealable closures.

The process utilizes two main carrier webs; a nonwoven web which formsan inner liner web, and an outer web that forms an outwardly facinglayer in the finished diaper. In a representative chassis process, thenonwoven web is slit at a slitter station by rotary knives along threelines, thereby forming four webs. One of the lines is on approximatelythe centerline of the web and the other two lines are parallel to andspaced a short distance from the centerline. The effect of such slicingis twofold; first, to separate the nonwoven web into two inner diaperliners. One liner will become the inside of the front of the diaper, andthe second liner will become the inside of the back of that garment.Second, two separate, relatively narrow strips are formed that may besubsequently used to cover and entrap portions of the leg-hole elastics.The strips can be separated physically by an angularly disposed spreaderroll and aligned laterally with their downstream target positions on theinner edges of the formed liners.

After the nonwoven web is sliced, an adhesive is applied to the linersin a predetermined pattern in preparation to receive leg-hole elastic.The leg-hole elastic is applied to the liners and then covered with thenarrow strips previously separated from the nonwoven web. Adhesive isapplied to the outer web, which is then combined with the assembledinner webs having elastic thereon, thereby forming the diaper chassis.Next, after the elastic members have been sandwiched between the innerand outer webs, an adhesive is applied to the chassis. The chassis isnow ready to receive an insert.

To assemble the final diaper product, the insert must be combined withthe chassis. The placement of the insert onto the chassis occurs on aplacement drum or at a patch applicator. The inserts are provided to thechassis on the placement drum at a desired pitch or spacing. Thegenerally flat chassis/insert combination is then folded so that theinner webs face each other, and the combination is trimmed. A sealerbonds the webs at appropriate locations prior to individual diapersbeing cut from the folded and sealed webs.

The current practice in applying a stretchable web such as a poly web toa second web is involved continuously feeding the poly web into theprocess which results in poly running full length of product, oralternatively, full length of a constructed insert core which is thenplaced onto a nonwoven-type chassis. Not all machine configurations canbe adapted from a full length poly chassis to a poly insertconfiguration due to space and/or cost restrictions. It should beunderstood that application of the poly web along the entire length ofthe product, rather than only where it is useful, increases the amountof poly material which must be utilized. This is a waste of the materialresource and adds additional cost to the product. It is thereforedesirable to create a lower cost product by putting poly into theproduct only where it is useful, instead of the complete product.

However, typical slip/cut application of poly patch to a continuous webdoes not work well because of the elasticity of the poly web. Theslip/cut process allows the poly to slip on anvil prior to being cutcausing the poly to violently snap back at the moment of cut. This canresult in a short patch-long patch output from the slip/cut where one ormore of the resulting poly patches are extremely distorted on thecarrier web.

In certain instances, it is desirable to eliminate or minimize the useof adhesives in the manufacturing process. This results in a materialsavings. Also, it is desirable to reduce significant strains applied toelongated elastics that are held under significant strain of 50-400%. Atthis level of elongation, there is a lot of stress on the elastic andthe elastic has an increased likelihood of breaking, which can lead tomachine downtime.

In prior art systems, such as U.S. Pat. No. 6,291,039, it is known tocapture elastics between layers of nonwoven materials. For instance, astaught therein, elastics can be placed into a hem of nonwoven material,and when the nonwoven material is bonded onto itself at the hem, theelastic can be captured within the folded over layer of material.

In U.S. Pat. No. 7,642,398 an elasticized web has a gatherable substrateand a multi-strand elastic yarn affixed to the gatherable substrate at aplurality of fixation locations. So that the yarn can be affixed to thesubstrate without the use of an adhesive, the yarn is subjected toforces to create partial delamination of the yarn at the fixationlocations and a portion of the gatherable substrate is caused to passbetween the thus delaminated strands of the multi-strand elastic yarn. Apatterned surface is disclosed in which the distribution density ofraised heels varies over the surface area of the patterned surface. Thepatterned surface comprises one or more regions along the length of theyarn in which no raised heels are present, so that the elasticized webproduced using this patterned surface will have regions along the lengthof the elastic yarn at which no bonds are present. Accordingly, theelastic yarn will be able to move independently of the substrate orsubstrates in such regions.

SUMMARY OF THE INVENTION

One aspect of the invention is a method including providing a basenon-woven layer, and applying thereto an elastic strand, strip or web.Throughout the specification, nonwoven webs are referred to. Thereferences to nonwoven webs should be considered to extend to bondablewebs generally, but alternative web materials are considered within thescope the invention. Examples of bondable webs which could be used inthe present invention when nonwovens are referred to, are any film webs,including polypropylene or polyethylene. Commonly elastics are appliedunder elongation/tension to carrier webs. In the present invention,non-elongated elastics, or elastics at low tension, are provided to acarrier web. In one embodiment, the carrier web is accumulated invalleys and the elastic is bonded to the carrier web at peaks. Suchbonding could be done with, but not limited to, adhesives, ultrasonics,or pressure. After bonding, the carrier web is returned to itsunaccumulated state thereby elongating the elastic(s) in the process. Asimple relationship between the amount of material accumulated and thedistance between bond sites determines the final elongation, or strain,of the elastic(s).

In another embodiment of the present invention, elastic filaments can beseparated from one another through ultrasonic force, electrostaticseparation, or tension on the elastic yarn. With an electrostatic chargeon the elastic filaments, the filaments separate and the filaments andnonwoven layer bond with minimal severing of the filaments.

In another aspect of the present invention, elastics are captured withinlayers of nonwoven materials, with the elastics laid down and capturedbetween the nonwoven layers in a meandering pattern between bond pointsof nonwoven materials of the laminate. In this configuration,differently shaped and configured pins or protrusions on a roll or drumcan urge the elastics to meander between bond points. In other words,the elastics can be trained to run straight, curved, meandering, or anycombination of those lay down patterns, and then retained in thatlaydown position due to friction between the elastic material and thenonwoven material, particularly if the elastics are meandering throughnon-linear bond points.

Several pin and protrusion configurations (oblong, curved, rectangular,circular) can be used in different patterns on a rotating drum, such asvariably spaced patterns, offset patterns, curved patterns or the like,to establish a complex pattern of elastics meandering through bondpoints in the nonwoven layers capturing the elastics, and the frictionbetween the elastic and the material retains the elastic sufficiently inplace to minimized adhesive bonding between the elastics and thenonwoven required to create the laminate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an apparatus and method of forming an elasticlaminate;

FIG. 2 is a side view of an elastic laminate with an unstretched elasticand a slack base layer;

FIG. 3a is a side view of an elastic laminate with a tensioned elasticlayer and a stretched or tensioned base layer;

FIG. 3b is a side view of an elastic laminate with a tensioned elasticlayer and a stretched or tensioned base layer, and a second materiallayer coupled to the elastic layer;

FIG. 4a is a side view of an elastic laminate with a tensioned elasticlayer and a stretched or tensioned base layer, and a second materiallayer coupled to the base layer (or first material layer) at discretebond points, with the elastic layer positioned between the first andsecond material layers;

FIG. 4b is a side view of an alternate embodiment of the presentinvention, with pins (or anvil bond points) placed about an anvil rolland carrying the first material layer, and elastic strands laid atop thefirst non-woven layer tented by the pins, with a second material layerlaid over the elastic strands and first material layer, and thetrilaminate bonded together and passed downstream for furtherprocessing;

FIG. 4c is a perspective view of the machine of FIG. 4b , with elasticstrands laid down atop the first material layer, and the elastic strandsallowed to or encouraged to wander about the anvil bond points to belaid down and the first and second layers bonded at the bond points tosecure the elastics therebetween in meandering fashion;

FIG. 4d is a side view of a machine for joining the elastic and firstmaterial layer at bond points, bringing first material layer to a tautcondition, and bonding a second material layer to the laminate during asecond bonding operation;

FIG. 5 is a side view of the unit of FIG. 4c , showing the trilaminateformation, with the meandering elastics trapped between the bond pointsof the first and second layers;

FIG. 6 is an alternate embodiment of the pinned anvil arrangement, withslots provided about the anvil.

FIG. 7 is an alternate anvil bond point configuration;

FIG. 8 is a second alternate anvil bond point configuration encouragingcircuitous path of the elastic strands about the anvil bond points, thespaces between the anvil bond points (where the first and secondmaterial layers will become bonded, creating short tunnels to encouragethe lacing action of the elastics between these tunnels to limit creep);

FIG. 9 is a third alternate anvil bond point configuration;

FIG. 10 is a perspective view of elastic material contained in a singlematerial hem;

FIG. 11 is a perspective view of elastic material contained between twomaterials to create a trilaminate;

FIG. 12 is a fourth alternate anvil bond point configuration;

FIG. 13 is a fifth alternate anvil bond point configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention which may be embodied inother specific structures. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention.

It is noted that the present techniques and apparatus are describedherein with respect to products such as diapers, but as previouslymentioned, can be applied to a wide variety of processes in whichdiscrete components are applied sequentially.

Referring now to FIG. 1, a side view of an apparatus and method offorming an elastic laminate is shown. A base support structure 18 isprovided with peaks and valleys, which can be a “V” shape. A preferablynon-woven layer 12 is laid into the valleys. Atop the nonwoven 12 islaid an unstretched or relatively unstretched elastic layer 14, whichcan comprise strands or a web of elastic. This elastic 14 is bonded tothe non-woven layer 12 at bond points 16. Such bonding could be donewith, but not limited to, adhesives, ultrasonics, or pressure.

FIG. 2 is a side view of an elastic laminate with an unstretched elastic14, and a slack base layer 12, shown just after bonding the two layerstogether.

After bonding, the carrier web 12 is returned to its unaccumulated statethereby elongating the elastic(s) 14 in the process, as shown in FIG. 3a. If considered mathematically, a relationship between the amount ofmaterial accumulated within the valleys, and the distance between thepeaks determines the final elongation or strain (ε) of the elastics.Twice the distance from peak to valley, divided by the distance betweenpeaks, defines (ε) of the elastics. Put another way, twice the distancefrom peak to valley will measure the distance between bond points ofnonwoven 12 in a non-accumulated state.

If desired, as shown in FIG. 3b , a second material layer 20 (preferablynonwoven) can be coupled to the elastic 14, or in an alternateconfiguration, coupled to the first material layer (FIG. 4a ).

In an alternative embodiment of the present invention as shown in FIG. 4b, the forming technique described with reference to FIG. 4a is shown inside view in FIG. 4b . Pins or protrusions or anvil bond points 52 areplaced about an anvil roll 50, and elastic strands 14 laid atop anonwoven layer 12 tented by the pins 52. Adjacent tented nonwoven 12peaks create somewhat of a tunnel when coupled with top nonwoven 20, andelastic 14 is carried in the tunnel in circuitous or meandering ways asshown in FIG. 4c . The result is that the elastic 14 is restrained fromlateral (or cross-machine direction) movement by encountering bondpoints between the first and second material layers 12 and 20respectively, created by points 52 acting against ultrasonic horn 54.Alternatively, adhesives can be used in bonding.

Still referring to FIG. 4c , and also to FIG. 5, protrusions 52 on ananvil roll 50 carry nonwoven 12, and create a tenting effect by raisingthe portions of the nonwoven 12 carried by the protrusions 52. It isbetween and about these adjacent and downstream bond points that theelastic 14 is allowed to, or encouraged to, meander generally in themachine direction as opposed to traveling linearly in the machinedirection. Elastic 14 is laid down with tension in a circuitous pathover and about the protrusions 52. The elastic 14 forces the nonwoven 12down around protrusions 52 and the protrusions 52 are used toultrasonically bond a second, top nonwoven layer 20 to the firstnonwoven 12. The elastic 14 experiences a fairly high frictional forceagainst the bonded segments of the nonwoven layers 12 because of theserpentine (meandering) path of the elastic 14 about the bond points andagainst the material layers 12 and 20 themselves, keeping the elastic 14from creeping.

Referring now to FIG. 4d , a forming technique described with referenceto FIG. 3b is shown in side view in FIG. 4. In particular, after joininginitially relaxed elastic 14 and initially relaxed first material layer12 at bond points 16 by bonding unit 54, first material layer 12 andelastic layer 14 can be brought taut by elongating elastic 14. Afterfirst material layer 12 is sufficiently taut, second material layer 20(preferably non woven) is introduced to the laminate 12/14, and a secondbonding operation occurs between material layer 20 and laminate 12/14.This bonding can be performed by adhesive (not shown) or by anultrasonic horn 54 operating against drum 70.

Referring now to FIG. 6, an alternate embodiment of the pinned anvilarrangement of FIGS. 4 and 5 is shown, with slots 55 provided about theanvil roll 50. First nonwoven layer 12, and atop that layer, the elastic14 is laid down in slots 55, and a top nonwoven layer 20 is laid downand bonded to first nonwoven layer 12. This creates a tunnel ofnonwoven, and the tight elastic 14 is resistant to creeping as describedpreviously.

In addition to the techniques described above, modifications to thephysical properties of the elastic 14 can assist providing the desiredfrictional resistance between the elastic 14 and nonwoven 12. Forinstance, ultrasonic force applied to the strands can cause the strandsto unravel; those unraveled ends would choke any created tunnels in thenonwoven. Alternatively or additionally, the nonwoven layers 12 could bebonded through the unraveled strands 14, or could be unraveled withoutbonding.

Still alternatively or additionally, a polymer coating such as EthyleneVinyl Acetate (EVA) could be intermittently applied on the stretchedelastic strands 14, to create rings or collars of eventually solidifiedpolymer. The eventually solidified polymer on the elastic strands 14would provide a physical barrier on created or improvised tunnels andmight even get bonded into the nonwoven bonds that form the tunnel.

Still alternatively or additionally, two or more elastic strands 14, canbe twisted together, those entwined fibers 14 also physically resisttravel through the created tunnels as the elastic 14 tries to relax.Additionally, a single elastic strand 14 can be rolled to make a bulkytwisted structure that resists creep through the tunnel more effectivelythan elastic 14 that is simply stretched. Alternatively or additionally,the elastic 14 can be frayed or nicked with a rough surface such assandpaper; it may pull the individual fibers apart or roughen thesurface to fatten it up.

Referring now to FIG. 7, an alternate anvil bond point 52 configurationis shown. Bond points 52 are spaced apart in the machine direction byspacing y, and spaced apart in the cross-machine direction by spacing x.X and y can both vary and be variable between adjacent bond points 52.That is, the points can be closely spaced apart in the cross-machine ormachine directions, or more distantly spaced apart, and the spacing canvary from one row to the next, and from one column to the next.

For instance, as shown in a second alternate anvil bond pointconfiguration of FIG. 8, the bond points 52 can be spaced to encourage acircuitous path of the elastic strands 14 about the anvil bond points(noting that in a preferred embodiment that a nonwoven will be drapedover the bond points 52 and the nonwoven is not shown in FIG. 8). Inthis configuration, a cross machine direction spacing x′ offset isprovided in a column of bond points 52. The spaces between the anvilbond points 52 (where the first and second material layers 12 and 20will become bonded) creating short tunnels to encourage the lacingaction of the elastics 14 between these tunnels to limit creep.

Referring to FIG. 9, third alternate anvil bond point 52 configurationvaries machine direction spacing y′, y″ and y″ by an offset providedbetween adjacent rows of bond points 52. As such, both y and x can bevaried to encourage tunnel formation and encourage meandering elastics14. Alternatively as shown in FIG. 9, the protrusions can be staggeredsuch that protrusions of a first series of adjacent rows are notstaggered in the cross machine direction. This would encourage astraight run of elastics (at the top of FIG. 9), and downstream in themachine direction, a second series of adjacent rows can be staggered oroffset by a distance x′ to encourage a curved run (middle portion ofFIG. 9), or the staggering of x′ and y′ can be more random resulting ina meandering pattern of elastics 14.

Referring now to FIG. 10 elastic material 14 can be used in the presentinvention by single material hem of material 12. In this manner, themeandered elastic will be captured between a laminate of the firstmaterial 12 portions after folding over an outboard portion of web 12,for instance by a folding plow (not shown).

Referring now to FIG. 11, a perspective view of elastic material 14contained between two materials 12 and 14 to create a trilaminate isshown. As can be seen, the elastic 14 meanders around bond pointsbetween material layers 12 and 14.

Referring now to FIG. 12 is a fourth alternate anvil bond pointconfiguration is shown. A series of curved protrusions 56 can be usedinstead of or in addition to pins or protrusions 52 placed about ananvil roll 50 shown on FIGS. 4 and 5. In this embodiment, material layer12 is introduced atop the roll 50, and carried in part by curvedprotrusions 56. Material layer 12 will somewhat drape over and aboutprotrusions 56 to create channels encouraging elastic 14 to be laid downin a somewhat meandering pattern, such that when material layers 12 and20 are bonded (see, e.g., FIG. 4a ), the bond points between materiallayers 12 and 20 will result in friction between elastic 14 meanderingthrough the bond points of material layers 12 and 20. This frictionprevents elastic 14 from sliding or creeping, i.e., elastic 14 isgenerally retained by frictional forces in its laid down meanderingpattern.

Referring now to FIG. 13, shaped protrusions 58, generally havingpreferably rounded corners to prevent material defects as a result ofmachine processing, can be used. The shape of protrusions 58 can bechanged, with the spacing between shapes, and the shapes of theprotrusions 58 themselves changed to accommodate the creation offrictional holding forces between elastic 14 and material layers 12 and20, specifically between elastic 14 and bonding points between materiallayers 12 and 20 which elastic 14 is sandwiched between. Thisconfiguration shows a larger surface area bond point, and a patternedprofile of protrusions 52 is used to provide increased frictionalresistance between elastic 14, the surrounding layers 12 and 20 andtheir bond points. In essence, a maze is provided for the elastic 14 togo through during manufacture, and rounded corners of protrusions 52 canurge the elastic 14 to be laid down in those maze patterns during theelastic laydown and bonding processes previously described.

The foregoing is considered as illustrative only of the principles ofthe invention. Furthermore, since numerous modifications and changeswill readily occur to those skilled in the art, it is not desired tolimit the invention to the exact construction and operation shown anddescribed. While the preferred embodiment has been described, thedetails may be changed without departing from the invention, which isdefined by the claims.

What is claimed is:
 1. An elastic assembly comprising: a first layer ofmaterial and a second layer of material bonded together at a pluralityof bond points that are spaced apart from one another, the first andsecond layers of material having a lengthwise direction and a crosswisedirection; and a first elastic strand disposed between the first andsecond layers of material, the first elastic strand following anon-linear path in the lengthwise direction around respective spacedapart bond points; wherein the first elastic strand is positioned on afirst crosswise side of a first bond point and is positioned on a secondcrosswise side opposite a first crosswise side of a second bond pointthat is spaced apart from the first bond point in the lengthwisedirection; and wherein the plurality of bond points trap the firstelastic strand between the first and second layers.
 2. The elasticassembly of claim 1 comprising a plurality of tunnels defined by thefirst and second layers of material and by the plurality of bond points,with the first elastic strand positioned within a respective tunnel ofthe plurality of tunnels.
 3. The elastic assembly of claim 2 wherein africtional force between the first elastic strand and the first andsecond layers of material retains the first elastic strand in place. 4.The elastic assembly of claim 3 wherein the frictional force is createdby positioning of the first elastic strand within a respective tunnel ofthe plurality of tunnels and the non-linear path of the first elasticstrand in the lengthwise direction around respective spaced apart bondpoints creates.
 5. The elastic assembly of claim 2 further comprising asecond elastic strand disposed between the first and second layers ofmaterial.
 6. The elastic assembly of claim 5 wherein the second elasticstrand is spaced apart from the first elastic strand in the crosswisedirection, with the second elastic strand positioned on a firstcrosswise side of a third bond point and positioned on a secondcrosswise side opposite the first crosswise side of a fourth bond pointthat is spaced apart from the third bond point in the lengthwisedirection.
 7. The elastic assembly of claim 5 wherein the second elasticstrand is twisted together with the first elastic strand as entwinedfibers positioned within a respective tunnel of the plurality oftunnels, so as to resist travel therethrough.
 8. The elastic assembly ofclaim 1 wherein the first elastic strand is laid down on the first layerof material in a tensioned state.
 9. The elastic assembly of claim 1wherein, in following the non-linear path, the first elastic strandcomprises a plurality of straight segments generally extending in thelengthwise direction and following a circuitous path in the lengthwisedirection.
 10. The elastic assembly of claim 1 wherein the first layerof material and the second layer of material are formed from a singleweb of material, with the first layer of material comprising a firstportion of the single web of material and the second layer of materialcomprising a second portion of the single web of material that is foldedover the first portion.
 11. An elastic structure comprising: a firstlayer of material and a second layer of material bonded together at aplurality of bond points that are spaced apart from one another, thefirst and second layers of material having a lengthwise direction and acrosswise direction; and an elastic strand disposed between the firstand second layers of material, the elastic strand positioned between apair of upstream bond points spaced apart in the crosswise direction ata first upstream passage location and positioned between a pair ofdownstream bond points spaced apart in the crosswise direction at afirst downstream passage location, the first upstream passage locationoffset from the first downstream passage location in the crosswisedirection.
 12. The elastic structure of claim 11 wherein the elasticstrand is trapped between the pair of upstream bond points and the pairof downstream bond points, between the first and second layers ofmaterial, with friction between the elastic strand and the first andsecond layers of material retaining the elastic strand in place relativeto the first and second layers of material.
 13. The elastic structure ofclaim 11 wherein the elastic strand is positioned between another pairof downstream bond points spaced apart in the crosswise direction at asecond downstream passage location spaced apart lengthwise from thefirst downstream passage location, with the elastic strand traversing adirection line extending in the lengthwise direction multiple times asit follows a non-linear path.
 14. The elastic structure of claim 11comprising a plurality of tunnels defined by the first and second layersof material and by the plurality of bond points, with the elastic strandpositioned within a respective tunnel of the plurality of tunnels.
 15. Amethod of fabricating an elastic structure comprising: providing a firstlayer of material having a lengthwise direction and a crosswisedirection; laying down an elastic strand on the first layer of materialin a non-linear manner and such that the elastic strand extendsgenerally in the lengthwise direction; positioning a second layer ofmaterial on the first layer of material; and bonding the first andsecond layers of material together at a plurality of bond points;wherein the elastic strand is positioned between a pair of upstream bondpoints spaced apart in the crosswise direction at a first upstreampassage location and positioned between a pair of downstream bond pointsspaced apart in the crosswise direction at a first downstream passagelocation, the first upstream passage location offset from the firstdownstream passage location in the crosswise direction.
 16. The methodof claim 15 comprising trapping the elastic strand between the pair ofupstream bond points and the pair of downstream bond points, between thefirst and second layers of material.
 17. The method of claim 15comprising laying down the first elastic strand on the first layer ofmaterial in a tensioned state.
 18. The method of claim 15 whereinproviding the first layer of material comprises carrying the first layerof material on an anvil roll having a plurality of anvil bond points,the plurality of anvil bond points comprising protrusions on the anvilroll that raise portions of the first layer of material to provide atenting effect at the plurality of anvil bond points to enable layingdown of the elastic strand in the non-linear manner; and wherein layingdown the elastic strand comprises laying the elastic strand down on thefirst layer of material around a portion of the protrusions in thenon-linear manner.
 19. The method of claim 15 comprising laying down afirst portion of the elastic strand in the non-linear manner and layingdown a second portion of the elastic strand in a linear manner.
 20. Themethod of claim 15 comprising forming the first layer of material andthe second layer of material from a single web of material, and whereinpositioning the second layer of material on the first layer of materialcomprises folding the single web of material along a fold line extendingin the lengthwise direction.